Description

International Harvester L-110, L-120, L-130, L-150, L-160 Service Manual

You’ve got an L-110 or an L-160 on your lift, and you’re staring at a grease fitting you can’t identify. Or maybe you’re about to drain the transmission on an L-120 and you need to know if that old 90-weight is still right. Without the factory lubrication specs, you are guessing. Guessing on a 50-year-old truck gets you stripped threads, blown seals, and a shop full of smoke. That’s where this International Harvester L-110, L-120, L-130, L-150, L-160 Service Manual comes in. It’s not a reprint. It’s a direct scan of the original IH publication – 32 pages of what the engineers wrote, not what some aftermarket editor thought was close enough.

Lubrication Group: What the Factory Covers

Open Section A, and you get the whole lubrication story. General instructions on page 1 – not fluff, but actual guidance on how to select engine oil for your L-130’s gas or diesel mill. The manual lists oil types and classifications. Remember, this was written before modern API ratings, so it breaks down what military and commercial designations map to. You also get lubrication intervals for the chassis, clutch release bearings, water pumps, wheel bearings, and propeller shaft center bearings (the non-prelubricated type). That’s the kind of detail that stops you from over-greasing a u-joint and blowing the seal.

Engine Oil Selection and Types – What to Use

Pages 1 through 3 walk through engine oil types and selection. This is critical because an L-150 with a gas engine wants different viscosity than a diesel L-160. The manual gives you the straight dope on SAE grades for different ambient temperatures. If you’re running a rebuilt engine with modern rings, you still need to start from the factory recommendation and work up. I’ve seen guys dump 15W-40 into an old IH and wonder why the lifters clatter. Start with the spec in this manual, then adjust based on wear. Also covered: air cleaner oil – yes, oil bath cleaners need the right weight. Page 4 has the service schedule for those.

Unit Capacities and Axle Specs

Page 7 is the unit capacities table. That’s where you find exactly how many quarts the transmission on an L-110 takes, and what grade. Same for the double-reduction hypoid axles from Eaton and the Timken S-200, U-200, S-300, U-300 series. The manual breaks out single-speed and two-speed axles separately. If you’re swapping a rear end from a donor truck, you need these numbers to fill it right. Overfill a hypoid and it pukes out the vent. Underfill and you cook the pinion bearing. There’s no margin for error here.

Lubrication Charts for Each Model – L-110 Through L-160

Section B gives you two-page lubrication charts per truck series. L-110 is on pages 1-2, L-120 on 3-4, L-130 on 5-6, L-150 on 7-8, L-160 on 9-10. Each chart spells out every grease point, oil fill, and service interval. The charts are schematic – you get a diagram of the chassis with callouts. That’s how you find the grease fitting on the clutch release bearing without taking the bellhousing off. If you own multiple L-line trucks – say a fleet of L-120s and an L-150 – this single manual covers all of them. No need to buy five separate books.

Why OEM Documentation Beats Aftermarket

I trust factory manuals because they were written by the people who designed the truck. Aftermarket manuals often combine multiple years and collapse differences into a generic procedure. That gets you a wrong torque on a banjo bolt or a misplaced oil seal. This IH manual uses the original part numbers and shows the actual factory lubrication fittings. For example, the double-reduction Eaton axle lube spec – you won’t find that in a Chilton’s. Combine this with the International Harvester Cub Cadet Tractor Service Manual – OEM Factory Specs”>Cub Cadet tractor manual if you’re working on IH equipment, but for trucks, this is the one. Also check the International Harvester L-LINE R-LINE 2009 Service Manual”>L-LINE R-LINE 2009 Service Manual for later model variations. And if you have an IH garden tractor, the International Harvester 73, 106, 107, 126, 127 Service Manual – OEM Specs”>73, 106, 107, 126, 127 manual covers those.

For background on the engines used in these trucks, “>this Wikipedia article on diesel engines explains the pre-combustion chamber designs IH used. The transmission section references syncromesh and constant mesh designs – if you need to brush up on how those work, Manual Transmission”>Manual Transmission is a good primer. But the manual itself gives you the step-by-step: drain plug location, fill level, and oil type. Nothing else needed.

FAQ – Two Questions I Get All the Time

Does this manual cover diesel engines or just gas?

Both. The oil selection section addresses gasoline and diesel engines used in the L-110 through L-160 series. It lists specific oil classifications for each.

Can I use modern synthetic oil in my L-130 based on this manual’s recommendations?

The manual predates synthetic oils, but you can cross-reference the viscosity and service classification it specifies (e.g., MIL-L-2104B or API Service CC/CD) to modern equivalents. For example, if it calls for SAE 30 in summer, a modern 15W-40 diesel oil that meets API CK-4 will work, provided you check that it also meets the older CC/CD requirements. The manual gives the starting point – you match the viscosity grade and performance level. But don’t guess. Look up the exact oil type on page 2, then find a current product with that spec. I’ve seen guys run full synthetic 5W-20 in an L-120 and burn oil because the clearances are too loose. Stick to the original viscosity range unless you’ve rebuilt the engine.

This manual is a 32-page document, but it packs more usable data than a 400-page generic service book. Every time I pick it up, I find something I forgot – like the clutch release bearing grease interval or the Timken axle lube change schedule. If you’re restoring an L-110 or keeping an L-150 running for work, you need this on your bench, not on a shelf. Access the Factory Manual and get the oil right the first time.